Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b15a670568cf4ff…

MALICIOUS

PDF

80.9 KB Created: 2021-10-05 04:34:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 53f32be0b92b41595f49ef1dfc1f42cd SHA-1: 220cf949e38f72164aad129de6aa212b8ae85b50 SHA-256: 1b15a670568cf4ff131be5c94718f43ecdd62bd3c727a93d9415fce6a64ad50c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains embedded JavaScript, which is often used to exploit PDF vulnerabilities or redirect users. The presence of numerous URLs, including those hosted on compromised CMS uploads and disposable domains, suggests a link farm designed to obscure the ultimate destination, likely a phishing page or malware download site. The primary attack vector is likely spearphishing attachment, given the PDF format.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://aallergy.netlovestories.com/upload/files/kikilizonajepiwemu.pdf
    • https://autoradiator.mn/uploads/ckfinder/files/39234255235.pdf
    • http://candientu24h.vn/webroot/img/files/27976389558.pdf
    • http://pc75.net/upfiles/file/1631800453.pdf
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614873877a811---92113747705.pdf
    • https://merohamro.com/ckfinder/userfiles/files/xajivusidoponetemafe.pdf
    • https://vicareyou.com/userfiles/file/85164733871.pdf
    • http://focalthai.com/file_media/file_image/file/39547322373.pdf
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/161542715c8ee9---80977400918.pdf
    • https://marblobathware.com/app/webroot/img/files/16165097211.pdf
    • https://fier-forjat-valimet.ro/ckfinder/userfiles/files/zurazimimawokinimibobezon.pdf
    • http://hnht-electromagnet.com/d/files/ninipusavojabejivopiligi.pdf
    • http://polaryachts.com/res/wysiwyg/file/53596496890.pdf
    • http://dalhousieretreat.com/cote_dor_import/admin/ckfinder/userfiles/files/tamafujogavamerer.pdf
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/3lskj7olt3ufpjvpsbcbmp5etb/34020596580.pdf
    • https://somos.co/dleyes/admin/fotos/file/liboxesujelozowikamumomu.pdf
    • http://mkconline.com/landmark/ckfinder/userfiles/files/zokizasolugifividerizene.pdf
    • http://villaelen.it/userfiles/files/fitukisekepogijew.pdf
    • http://piri-piri.pl/ckfinder/userfiles/files/tudemibabononik.pdf
    • http://www.erealitysolutions.com/tennisontario/assets/appsadmin/js/ckfinder/userfiles/files/buramezubobemaj.pdf
    • http://tieulongcopro.com/luutru/files/56357954608.pdf
    • https://millvalley.com/wysiwygfiles/file/suripuwekobo.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=places+to+go+in+vermont
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d8e4.bin
07ce83fc4b8f970855d72706f71e87f25c9708cedc3194a91e15a0088d2c8700
pdf-font-stream PDF embedded font (sfnt) at offset 0xD8E4 17592 bytes
font_01_sfnt_off00010595.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10595 16792 bytes
font_02_sfnt_off00011dac.bin
52b1c27223469c8c5112b6008f9570584fbc6b1e5029683ae821b26251eb1aad
pdf-font-stream PDF embedded font (sfnt) at offset 0x11DAC 10640 bytes